gis: gdal: Features may now be fetched from OGR layers that do not support random access reading, but no more negative indexes are allowed; cleaned up OGRGeomType; moved test vector data into its own directory.

git-svn-id: http://code.djangoproject.com/svn/django/branches/gis@8034 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/contrib/gis/gdal/error.py

@@ -25,6 +25,7 @@ OGRERR_DICT = { 1 : (OGRException, 'Not enough data.'),
                 5 : (OGRException, 'Corrupt data.'),
                 6 : (OGRException, 'OGR failure.'),
                 7 : (SRSException, 'Unsupported SRS.'),
+                8 : (OGRException, 'Invalid handle.'),
                 }
 OGRERR_NONE = 0
 

django/contrib/gis/gdal/geometries.py

@@ -201,7 +201,13 @@ class OGRGeometry(object):
     @property
     def geom_type(self):
         "Returns the Type for this Geometry."
-        return OGRGeomType(get_geom_type(self._ptr))
+        try:
+            return OGRGeomType(get_geom_type(self._ptr))
+        except OGRException:
+            # VRT datasources return an invalid geometry type
+            # number, but a valid name -- we'll try that instead.
+            # See: http://trac.osgeo.org/gdal/ticket/2491
+            return OGRGeomType(get_geom_name(self._ptr))
 
     @property
     def geom_name(self):

django/contrib/gis/gdal/geomtype.py

@@ -4,31 +4,42 @@ from django.contrib.gis.gdal.error import OGRException
 class OGRGeomType(object):
     "Encapulates OGR Geometry Types."
 
-    # Ordered array of acceptable strings and their corresponding OGRwkbGeometryType
-    __ogr_str = ['Unknown', 'Point', 'LineString', 'Polygon', 'MultiPoint',
-                 'MultiLineString', 'MultiPolygon', 'GeometryCollection',
-                 'LinearRing']
-    __ogr_int = [0, 1, 2, 3, 4, 5, 6, 7, 101]
+    # Dictionary of acceptable OGRwkbGeometryType s and their string names.
+    _types = {0 : 'Unknown',
+              1 : 'Point',
+              2 : 'LineString',
+              3 : 'Polygon',
+              4 : 'MultiPoint',
+              5 : 'MultiLineString',
+              6 : 'MultiPolygon',
+              7 : 'GeometryCollection',
+              100 : 'None',
+              101 : 'LinearRing',
+              }
+    # Reverse type dictionary, keyed by lower-case of the name.
+    _str_types = dict([(v.lower(), k) for k, v in _types.items()])
 
     def __init__(self, type_input):
         "Figures out the correct OGR Type based upon the input."
         if isinstance(type_input, OGRGeomType):
-            self._index = type_input._index
+            num = type_input.num
         elif isinstance(type_input, basestring):
-            idx = self._has_str(self.__ogr_str, type_input)
-            if idx == None:
+            num = self._str_types.get(type_input.lower(), None)
+            if num is None:
                 raise OGRException('Invalid OGR String Type "%s"' % type_input)
-            self._index = idx
         elif isinstance(type_input, int):
-            if not type_input in self.__ogr_int:
+            if not type_input in self._types:
                 raise OGRException('Invalid OGR Integer Type: %d' % type_input)
-            self._index =  self.__ogr_int.index(type_input)
+            num = type_input
         else:
             raise TypeError('Invalid OGR input type given.')
+        
+        # Setting the OGR geometry type number.
+        self.num = num
 
     def __str__(self):
-        "Returns a short-hand string form of the OGR Geometry type."
-        return self.__ogr_str[self._index]
+        "Returns the value of the name property."
+        return self.name
 
     def __eq__(self, other):
         """
@@ -36,37 +47,27 @@ class OGRGeomType(object):
         other OGRGeomType, the short-hand string, or the integer.
         """
         if isinstance(other, OGRGeomType):
-            return self._index == other._index
+            return self.num == other.num
         elif isinstance(other, basestring):
-            idx = self._has_str(self.__ogr_str, other)
-            if not (idx == None): return self._index == idx
-            return False
+            return self.name.lower() == other.lower()
         elif isinstance(other, int):
-            if not other in self.__ogr_int: return False
-            return self.__ogr_int.index(other) == self._index
+            return self.num == other
         else:
-            raise TypeError('Cannot compare with type: %s' % str(type(other)))
+            return False
 
     def __ne__(self, other):
         return not (self == other)
 
-    def _has_str(self, arr, s):
-        "Case-insensitive search of the string array for the given pattern."
-        s_low = s.lower()
-        for i in xrange(len(arr)):
-            if s_low == arr[i].lower(): return i
-        return None
+    @property
+    def name(self):
+        "Returns a short-hand string form of the OGR Geometry type."
+        return self._types[self.num]
 
     @property
     def django(self):
         "Returns the Django GeometryField for this OGR Type."
-        s = self.__ogr_str[self._index]
-        if s in ('Unknown', 'LinearRing'):
+        s = self.name
+        if s in ('Unknown', 'LinearRing', 'None'):
             return None
         else:
             return s + 'Field'
-
-    @property
-    def num(self):
-        "Returns the OGRwkbGeometryType number for the OGR Type."
-        return self.__ogr_int[self._index]

django/contrib/gis/gdal/layer.py

@@ -14,7 +14,7 @@ from django.contrib.gis.gdal.prototypes.ds import \
     get_extent, get_fd_geom_type, get_fd_name, get_feature, get_feature_count, \
     get_field_count, get_field_defn, get_field_name, get_field_precision, \
     get_field_width, get_field_type, get_layer_defn, get_layer_srs, \
-    get_next_feature, reset_reading
+    get_next_feature, reset_reading, test_capability
 from django.contrib.gis.gdal.prototypes.srs import clone_srs
 
 # For more information, see the OGR C API source code:
@@ -32,29 +32,29 @@ class Layer(object):
             raise OGRException('Cannot create Layer, invalid pointer given')
         self._ptr = layer_ptr
         self._ldefn = get_layer_defn(self._ptr)
+        # Does the Layer support random reading?
+        self._random_read = self.test_capability('RandomRead')
 
     def __getitem__(self, index):
         "Gets the Feature at the specified index."
-        if not isinstance(index, (slice, int)):
-            raise TypeError
-        end = self.num_feat
-        if isinstance(index,int):
-            # An integer index was given
-            if index < 0:
-                index = end - index
-            if index < 0 or index >= self.num_feat:
-                raise OGRIndexError('index out of range')
+        if isinstance(index, (int, long)):
+            # An integer index was given -- we cannot do a check based on the
+            # number of features because the beginning and ending feature IDs
+            # are not guaranteed to be 0 and len(layer)-1, respectively.
+            if index < 0: raise OGRIndexError('Negative indices are not allowed on OGR Layers.')
             return self._make_feature(index)
-        else: 
+        elif isinstance(index, slice):
             # A slice was given
-            start, stop, stride = index.indices(end)
-            return [self._make_feature(offset) for offset in range(start,stop,stride)]
+            start, stop, stride = index.indices(self.num_feat)
+            return [self._make_feature(fid) for fid in xrange(start, stop, stride)]
+        else:
+            raise TypeError('Integers and slices may only be used when indexing OGR Layers.')
 
     def __iter__(self):
         "Iterates over each Feature in the Layer."
         # ResetReading() must be called before iteration is to begin.
         reset_reading(self._ptr)
-        for i in range(self.num_feat):
+        for i in xrange(self.num_feat):
             yield Feature(get_next_feature(self._ptr), self._ldefn)
 
     def __len__(self):
@@ -65,9 +65,26 @@ class Layer(object):
         "The string name of the layer."
         return self.name
 
-    def _make_feature(self, offset):
-        "Helper routine for __getitem__ that makes a feature from an offset."
-        return Feature(get_feature(self._ptr, offset), self._ldefn)
+    def _make_feature(self, feat_id):
+        """
+        Helper routine for __getitem__ that constructs a Feature from the given
+        Feature ID.  If the OGR Layer does not support random-access reading,
+        then each feature of the layer will be incremented through until the
+        a Feature is found matching the given feature ID.
+        """
+        if self._random_read:
+            # If the Layer supports random reading, return.
+            try:
+                return Feature(get_feature(self._ptr, feat_id), self._ldefn)
+            except OGRException:
+                pass
+        else:
+            # Random access isn't supported, have to increment through
+            # each feature until the given feature ID is encountered.
+            for feat in self:
+                if feat.fid == feat_id: return feat
+        # Should have returned a Feature, raise an OGRIndexError.    
+        raise OGRIndexError('Invalid feature id: %s.' % feat_id)
 
     #### Layer properties ####
     @property
@@ -158,3 +175,13 @@ class Layer(object):
             return [GEOSGeometry(feat.geom.wkb) for feat in self]
         else:
             return [feat.geom for feat in self]
+
+    def test_capability(self, capability):
+        """
+        Returns a bool indicating whether the this Layer supports the given
+        capability (a string).  Valid capability strings include:
+          'RandomRead', 'SequentialWrite', 'RandomWrite', 'FastSpatialFilter',
+          'FastFeatureCount', 'FastGetExtent', 'CreateField', 'Transactions',
+          'DeleteFeature', and 'FastSetNextByIndex'.
+        """
+        return bool(test_capability(self._ptr, capability))

django/contrib/gis/gdal/prototypes/ds.py

@@ -37,6 +37,7 @@ get_layer_defn = voidptr_output(lgdal.OGR_L_GetLayerDefn, [c_void_p])
 get_layer_srs = srs_output(lgdal.OGR_L_GetSpatialRef, [c_void_p])
 get_next_feature = voidptr_output(lgdal.OGR_L_GetNextFeature, [c_void_p])
 reset_reading = void_output(lgdal.OGR_L_ResetReading, [c_void_p], errcheck=False)
+test_capability = int_output(lgdal.OGR_L_TestCapability, [c_void_p, c_char_p])
 
 ### Feature Definition Routines ###
 get_fd_geom_type = int_output(lgdal.OGR_FD_GetGeomType, [c_void_p])

django/contrib/gis/tests/data/test_vrt/test_vrt.csv

@@ -0,0 +1,4 @@
+POINT_X,POINT_Y,NUM
+1.0,2.0,5
+5.0,23.0,17
+100.0,523.5,23

django/contrib/gis/tests/data/test_vrt/test_vrt.vrt

@@ -0,0 +1,7 @@
+<OGRVRTDataSource>
+<OGRVRTLayer name="test_vrt">
+<SrcDataSource relativeToVRT="1">test_vrt.csv</SrcDataSource>
+<GeometryType>wkbPoint</GeometryType>
+<GeometryField encoding="PointFromColumns" x="POINT_X" y="POINT_Y" z="NUM"/>
+</OGRVRTLayer>
+</OGRVRTDataSource>

django/contrib/gis/tests/test_gdal_ds.py

@@ -3,27 +3,38 @@ from django.contrib.gis.gdal import DataSource, Envelope, OGRException, OGRIndex
 from django.contrib.gis.gdal.field import OFTReal, OFTInteger, OFTString
 
 # Path for SHP files
-shp_path = os.path.dirname(__file__)
-def get_shp(name):
-    return shp_path + os.sep + name + os.sep + name + '.shp'
+data_path = os.path.join(os.path.dirname(__file__), 'data')
+def get_ds_file(name, ext):
+    return os.sep.join([data_path, name, name + '.%s' % ext])
 
 # Test SHP data source object
-class TestSHP:
-    def __init__(self, shp, **kwargs):
-        self.ds = get_shp(shp)
+class TestDS:
+    def __init__(self, name, **kwargs):
+        ext = kwargs.pop('ext', 'shp')
+        self.ds = get_ds_file(name, ext)
         for key, value in kwargs.items():
             setattr(self, key, value)
 
 # List of acceptable data sources.
-ds_list = (TestSHP('test_point', nfeat=5, nfld=3, geom='POINT', gtype=1, fields={'dbl' : OFTReal, 'int' : OFTInteger, 'str' : OFTString,},
-                   extent=(-1.35011,0.166623,-0.524093,0.824508), # Got extent from QGIS
-                   srs_wkt='GEOGCS["GCS_WGS_1984",DATUM["WGS_1984",SPHEROID["WGS_1984",6378137,298.257223563]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]]'),
-           TestSHP('test_poly', nfeat=3, nfld=3, geom='POLYGON', gtype=3, fields={'float' : OFTReal, 'int' : OFTInteger, 'str' : OFTString,},
-                   extent=(-1.01513,-0.558245,0.161876,0.839637), # Got extent from QGIS
-                   srs_wkt='GEOGCS["GCS_WGS_1984",DATUM["WGS_1984",SPHEROID["WGS_1984",6378137,298.257223563]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]]'),
+ds_list = (TestDS('test_point', nfeat=5, nfld=3, geom='POINT', gtype=1, driver='ESRI Shapefile',
+                  fields={'dbl' : OFTReal, 'int' : OFTInteger, 'str' : OFTString,},
+                  extent=(-1.35011,0.166623,-0.524093,0.824508), # Got extent from QGIS
+                  srs_wkt='GEOGCS["GCS_WGS_1984",DATUM["WGS_1984",SPHEROID["WGS_1984",6378137,298.257223563]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]]',
+                  field_values={'dbl' : [float(i) for i in range(1, 6)], 'int' : range(1, 6), 'str' : [str(i) for i in range(1, 6)]},
+                  fids=range(5)),
+           TestDS('test_vrt', ext='vrt', nfeat=3, nfld=3, geom='POINT', gtype=1, driver='VRT',
+                  fields={'POINT_X' : OFTString, 'POINT_Y' : OFTString, 'NUM' : OFTString}, # VRT uses CSV, which all types are OFTString.
+                  extent=(1.0, 2.0, 100.0, 523.5), # Min/Max from CSV
+                  field_values={'POINT_X' : ['1.0', '5.0', '100.0'], 'POINT_Y' : ['2.0', '23.0', '523.5'], 'NUM' : ['5', '17', '23']},
+                  fids=range(1,4)),
+           TestDS('test_poly', nfeat=3, nfld=3, geom='POLYGON', gtype=3, 
+                  driver='ESRI Shapefile',
+                  fields={'float' : OFTReal, 'int' : OFTInteger, 'str' : OFTString,},
+                  extent=(-1.01513,-0.558245,0.161876,0.839637), # Got extent from QGIS
+                  srs_wkt='GEOGCS["GCS_WGS_1984",DATUM["WGS_1984",SPHEROID["WGS_1984",6378137,298.257223563]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]]'),
            )
 
-bad_ds = (TestSHP('foo'),
+bad_ds = (TestDS('foo'),
           )
 
 class DataSourceTest(unittest.TestCase):
@@ -42,7 +53,7 @@ class DataSourceTest(unittest.TestCase):
             self.assertEqual(source.ds, ds.name)
 
             # Making sure the driver name matches up
-            self.assertEqual('ESRI Shapefile', str(ds.driver))
+            self.assertEqual(source.driver, str(ds.driver))
 
             # Making sure indexing works
             try:
@@ -57,20 +68,17 @@ class DataSourceTest(unittest.TestCase):
         for source in bad_ds:
             self.assertRaises(OGRException, DataSource, source.ds)
 
-    def test03_layers(self):
+    def test03a_layers(self):
         "Testing Data Source Layers."
-
+        print "\nBEGIN - expecting out of range feature id error; safe to ignore.\n"
         for source in ds_list:
             ds = DataSource(source.ds)
 
-            # Incrementing through each layer, this tests __iter__
+            # Incrementing through each layer, this tests DataSource.__iter__
             for layer in ds:                
                 # Making sure we get the number of features we expect
                 self.assertEqual(len(layer), source.nfeat)
 
-                layer[0] #can index
-                layer[:1] #can slice
-
                 # Making sure we get the number of fields we expect
                 self.assertEqual(source.nfld, layer.num_fields)
                 self.assertEqual(source.nfld, len(layer.fields))
@@ -85,6 +93,42 @@ class DataSourceTest(unittest.TestCase):
                 # Now checking the field names.
                 flds = layer.fields
                 for f in flds: self.assertEqual(True, f in source.fields)
+                
+                # Negative FIDs are not allowed.
+                self.assertRaises(OGRIndexError, layer.__getitem__, -1)
+                self.assertRaises(OGRIndexError, layer.__getitem__, 50000)
+
+                if hasattr(source, 'field_values'):
+                    fld_names = source.field_values.keys()
+
+                    # Testing `Layer.get_fields` (which uses Layer.__iter__)
+                    for fld_name in fld_names:
+                        self.assertEqual(source.field_values[fld_name], layer.get_fields(fld_name))
+
+                    # Testing `Layer.__getitem__`.
+                    for i, fid in enumerate(source.fids):
+                        feat = layer[fid]
+                        self.assertEqual(fid, feat.fid)
+                        # Maybe this should be in the test below, but we might as well test
+                        # the feature values here while in this loop.
+                        for fld_name in fld_names:
+                            self.assertEqual(source.field_values[fld_name][i], feat.get(fld_name))
+        print "\nEND - expecting out of range feature id error; safe to ignore."
+                        
+    def test03b_layer_slice(self):
+        "Test indexing and slicing on Layers."
+        # Using the first data-source because the same slice
+        # can be used for both the layer and the control values.
+        source = ds_list[0]
+        ds = DataSource(source.ds)
+
+        sl = slice(1, 3)
+        feats = ds[0][sl]
+
+        for fld_name in ds[0].fields:
+            test_vals = [feat.get(fld_name) for feat in feats]
+            control_vals = source.field_values[fld_name][sl]
+            self.assertEqual(control_vals, test_vals)
 
     def test04_features(self):
         "Testing Data Source Features."
@@ -95,7 +139,8 @@ class DataSourceTest(unittest.TestCase):
             for layer in ds:
                 # Incrementing through each feature in the layer
                 for feat in layer:
-                    # Making sure the number of fields is what's expected.
+                    # Making sure the number of fields, and the geometry type
+                    # are what's expected.
                     self.assertEqual(source.nfld, len(list(feat)))
                     self.assertEqual(source.gtype, feat.geom_type)
 
@@ -105,7 +150,7 @@ class DataSourceTest(unittest.TestCase):
                         # a string value index for the feature.
                         self.assertEqual(True, isinstance(feat[k], v))
 
-                    # Testing __iter__ on the Feature
+                    # Testing Feature.__iter__
                     for fld in feat: self.assertEqual(True, fld.name in source.fields.keys())
                         
     def test05_geometries(self):
@@ -123,8 +168,10 @@ class DataSourceTest(unittest.TestCase):
                     self.assertEqual(source.gtype, g.geom_type)
 
                     # Making sure the SpatialReference is as expected.
-                    self.assertEqual(source.srs_wkt, g.srs.wkt)
-                        
+                    if hasattr(source, 'srs_wkt'):
+                        self.assertEqual(source.srs_wkt, g.srs.wkt)
+
+
 def suite():
     s = unittest.TestSuite()
     s.addTest(unittest.makeSuite(DataSourceTest))

django/contrib/gis/tests/test_gdal_geom.py

@@ -36,6 +36,11 @@ class OGRGeomTest(unittest.TestCase):
         self.assertEqual(False, OGRGeomType(1) != OGRGeomType('point'))
         self.assertEqual(True, OGRGeomType('POINT') != OGRGeomType(6))
 
+        # Testing the Django field name equivalent property.
+        self.assertEqual('PointField', OGRGeomType('Point').django)
+        self.assertEqual(None, OGRGeomType('Unknown').django)
+        self.assertEqual(None, OGRGeomType('none').django)
+
     def test01a_wkt(self):
         "Testing WKT output."
         for g in wkt_out: